"Cannonballs" and psammoma bodies: unusual cytologic features of metastatic pulmonary small-cell carcinoma in a pleural effusion

Our plain-English summary of "Cannonballs" and psammoma bodies: unusual cytologic features of metastatic pulmonary small-cell carcinoma in a pleural effusion, by A.B. Conway, M.K. Hart, J. Jessurun, et al (Diagnostic Cytopathology, 2013).

The study

• Authors: A.B. Conway, M.K. Hart, J. Jessurun, S.E. Pambuccian
• Journal: Diagnostic Cytopathology
• Published: 2013;41(3):247-52
• Type of article: Case report
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Large three-dimensional cell aggregates and psammoma bodies are usually encountered in benign serous effusions (mesothelial hyperplasia and endosalpingiosis), mesotheliomas, and metastatic papillary carcinomas. We report a case of pulmonary small-cell carcinoma occurring in an 88-year-old woman that initially presented with a malignant pleural effusion characterized cytologically by a predominance of large three-dimensional neoplastic cell aggregates ("cannonballs"), associated with rare psammoma bodies. Although the crowded three-dimensional tumor-cell aggregates did not allow detailed cytologic examination, the diagnosis of metastatic small-cell carcinoma could be established noting the characteristic chromatin features of the occasional single neoplastic cells and the characteristic "cell-in-cell" and "stack-of-coins" arrangements of rare small clusters of neoplastic cells. Immunoperoxidase stains showing positivity of the tumor cells for CD56, synaptophysin, and TTF1 further supported this diagnosis. Endobronchial ultrasound-guided fine-needle aspiration of a mediastinal lymph node subsequently confirmed the diagnosis of pulmonary small-cell carcinoma. Metastatic pulmonary small-cell carcinoma should be considered in the differential diagnosis of serous effusions showing large three-dimensional neoplastic cell aggregates and psammoma bodies to prevent a potential diagnostic pitfall.

Copyright © 2011 Wiley Periodicals, Inc.

In plain English

This brief report described one patient: an 88-year-old woman with a 20-pack-year smoking history who had flulike symptoms, chest pain, worsening shortness of breath and hoarseness. Imaging showed a mass at the left hilum of the lung and fluid around the left lung (a pleural effusion). Examination of 30 ml of this fluid showed small-cell carcinoma, a type of lung cancer. A needle sample from mediastinal lymph nodes later confirmed this diagnosis. A PET-CT scan also found active lesions in the liver, lymph nodes and left pleura. What was unusual was how the cancer cells looked in the fluid. They formed large ball-shaped clumps of over 100 cells ("cannonballs"). A few clumps also contained psammoma bodies (small round, layered deposits), and occasional ones lay free in the fluid. The authors said these features are typical of mesotheliomas and metastatic adenocarcinomas. The diagnosis rested on the chromatin of occasional single cells and "cell-in-cell" and "stack-of-coins" arrangements in rare small clusters. Stains positive for CD56, synaptophysin and TTF1 supported it. The authors concluded that this pattern could be a diagnostic pitfall. The report did not mention asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (brief report of a single patient)
• Who was studied: One 88-year-old woman with a left hilar lung mass and left pleural effusion, first seen at an outside hospital; dates of care not given
• Exposure: No asbestos exposure is described. The report notes a 20-pack-year smoking history.
• Main results:
  • Pleurocentesis obtained 30 ml of fluid. Cytologic examination of the fluid revealed small-cell carcinoma.
  • The pleural fluid showed numerous large three-dimensional aggregates of tumor cells ("cannonballs") made of over 100 cells, measuring 60 to over 600 micrometres in diameter
  • Rare aggregates contained round, concentrically laminated concretions 25 to 50 micrometres across, characteristic of psammoma bodies
  • Occasional single psammoma bodies, not associated with cells, were also present in the slide background
  • A peripheral layer of mesothelial cells rimmed the large tumor-cell aggregates
  • The diagnosis of metastatic small-cell carcinoma could be established from the characteristic chromatin features of occasional single neoplastic cells and the characteristic "cell-in-cell" and "stack-of-coins" arrangements of rare small clusters of neoplastic cells
  • The tumor cells were positive for synaptophysin, CD56 and TTF1, and negative for chromogranin, CK5/6, CK20, calretinin and WT1
  • Endobronchial ultrasound-guided fine needle aspiration of level 4L mediastinal lymph nodes was diagnosed as small-cell carcinoma
  • PET-CT identified hypermetabolic lesions in the right lobe of the liver, mediastinal and upper abdominal lymph nodes, and left pleura
• The authors' conclusion: The authors concluded that three-dimensional cell aggregates and psammoma bodies in effusions, which are typical of mesotheliomas and metastatic adenocarcinomas, could be a diagnostic pitfall. In their view, small-cell carcinoma should be considered when these features are seen in pleural fluid.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Carcinoma, Pleural Effusion, Reactive Mesothelial Hyperplasia, Mesothelioma, Ultrasound, Fine-Needle Aspiration, Differential Diagnosis.

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